This invention relates to a pull-on disposable diaper provided with fastening tape to fasten the diaper in its rolled-up state for disposal after the diaper has been used.
The Japanese Patent Publication A No. 1997-253123 describes a disposable diaper comprising a topsheet, a backsheet and an absorbent core disposed between these two sheets so as to configure a front waist region, a rear waist region and a crotch region extending between these two waist regions. At the front or rear waist region the backsheet is provided on the outer surface thereof with a single strip of fastening tape adapted to secure the used diaper in its rolled-up state for disposal. More specifically, the strip of fastening tape extends circumferentially of the diaper and has its longitudinally middle portion fixed to the diaper and its longitudinally opposite end portions folded-up so that these end portions may be unfolded when it is desired to use this strip of fastening tape. The longitudinally opposite end portions are coated with pressure-sensitive adhesive by means of which these end portions are maintained in a folded-up state.
Japanese Patent Publication A No. 1997-253124 describes a disposable diaper comprising a topsheet, a backsheet and an absorbent core disposed between these two sheets so as to configure a front waist region, a rear waist region and a crotch region extending between these two waist regions. At the front or rear waist region the backsheet is provided on the outer surface thereof with fastening tape adapted to secure the used diaper in its rolled-up state for disposal.
In this prior art diaper, the fastening tape comprises at least two strips of adhesive tape extending in parallel to each other circumferentially of the diaper.
For disposal, these diapers of prior art are similar to each other in that the strip(s) of fastening tape is (are) wound around the outer peripheral surface of the diaper which has been used and rolled up from its transversely opposite side edges and fixed to the outer peripheral surface of the used diaper.
Certainly, it is possible with these diapers described in the above-mentioned Publications to hold the used diaper in its rolled-up state by securing the rolled-up diaper substantially at a middle level of the diaper. However, it is impossible for these diapers to close the waist-opening of the diaper utilizing the strip(s) of fastening tape. Even after the used diaper has been tightly rolled up from its transversely opposite side edges, the waist-opening remains free and there is concern that excretion itself or its odor might leak through the waist-opening.
It is an object of this invention to provide a pants-type disposable diaper adapted to be held in its rolled-up state for disposal without any anxiety that excretion itself or its odor might leak through the waist-opening and/or the leg-openings.
According to this invention, there is provided a pants-type disposable diaper comprising a liquid-pervious topsheet, a liquid-impervious backsheet and a liquid-absorbent core disposed between the topsheet and the backsheet to define a front waist region, a rear waist region and a crotch region extending between the front and rear waist regions. The front and rear waist regions are placed upon each other with the topsheet inside along respective transversely opposite side edges of the diaper and are bonded together to define a waist-opening and a pair of leg-openings wherein the waist-opening and the pair of leg-openings have an elastic stretchability circumferentially thereof. The diaper is provided on an outer surface of the backsheet with fastening tape strips adapted to hold the diaper in a rolled-up state thereof for disposal after the diaper has been used.
This invention further includes fastening tape strips that are provided in a vicinity of the transversely opposite side edges of at least one of the front and rear waist regions. Each of the fastening tape strips is formed by a first portion extending in parallel to the side edges longitudinally of the diaper and a second portion extending from a predetermined region of the first portion longitudinally or transversely of the diaper, the first portion having longitudinally opposite end regions thereof bonded to the diaper in a vicinity of an edge of the waist-opening and in a vicinity of an edge of a respective one of the pair of leg-openings so that at least one of an intermediate region extending between the longitudinally opposite end regions of the first portion and the second portion defines an anchoring zone adapted to be removably anchored on an outer peripheral surface of the rolled-up diaper.
In the pull-on disposable diaper according to this invention, the respective first portions of the fastening tape strips have their longitudinally opposite ends secured to the respective peripheral edges of the waist- and leg-openings in contiguousness to elastic members secured under tension to the respective peripheral edges of the waist- and leg-openings so that the respective elastic members may be stretched outward transversely of the diaper as the respective fastening tape strips are pulled outward transversely of the diaper.
The fastening tape strips can be wound and anchored on the outer peripheral surface of the rolled-up diaper to hold the diaper in its rolled-up state and tensile force generated in the respective elastic members maintain the waist-opening and the leg-openings in a closed state. As a result, there is no anxiety that these openings might loosen and excretion or its odor might leak through these openings.
According to one embodiment of the diaper, the fastening tape strips can be extended to describe curves which are convex outward transversely of the diaper. In this embodiment, the fastening tape strips can be anchored on the outer peripheral surface of the diaper more firmly than the fastening tape strips extending rectilinearly. In this way, it is avoided that the fastening tape strips anchored on the outer peripheral surface of the diaper might be unintentionally peeled off therefrom.
According to another embodiment of the diaper, in which the second portions of the respective fastening tape strips extend outward from the intermediate regions of the first portions and are folded back so that they may be unfolded outward transversely of the diaper after the diaper has been used, the second portions do not extend outward transversely of the diaper before and during actual use of the diaper. In this way, the fastening tape strips can be provided in the vicinity of the side edges of the diaper and the second portions do not obstruct handling of the diaper.